Apparatus for loading high explosive shells



11m 29, 1943'. u, "THOMPSON, JR

APPARATUS FOR LOADING HIGH EXPLOSIVE SHELLS Filed March 50, 1942 7.2 Sheets-Sheet l June 29, 1943. u. THOMPSON, JR

APPARATUS FOR LOADING HIGH EXPLOSIVE SHELLS 2 Sheets-Sheet 2 Filed March 30 1942 Patented June 29, 1943 APPARATUS FOR LOADING HIGH EXPLOSIVE SHELLS Uldric Thompson, Jr NewYork, N. Y.

Application March 30, 1942, Serial No. 436,874

In Canada August 28, 1939 8 Claims.

This invention relates to the art of loading shells, bombs, boosters, and other explosive projectiles or parts thereof.

In the manufacture of ordnance projectiles, it is customary to employ a metal shell body having an internal chamber for the reception of the explosive material, which may be of any selected type. The present invention will be described with respect to high explosive charges such as T. N. T., Amatol, and the like, but is not to be considered as limited to any of these materials. Projectiles of the type mentioned are usually exploded by means of a booster or detonator which is activated by th shock caused by the impact of the projectile with the target, or by time fuses. Such projectiles may carry the detonator in the nose end or in the base end;

The charge-carrying chamber of th shell is usually filled by pouring an excess amount of the explosive while in a molten state, into the same through the detonator-receiving opening, a "riser head or funnel being used for this purpose until saidopenihg is also filled therewith. The pouring method of filling the projectiles, just referred to, has the important advantage that an homogeneous body of explosive within th shell body is provided which is entirely free of pipes, blow holes and the like imperfections. After the explosive has solidified it is necessary to remove a portion thereof to provide an axially disposed recess which will be complementa'l to the booster or detonator. It is highly essential that this operation be performed with minute accuracy, so as to provide a recess which will freely and yet snugly receive the booster or'detonator in such manner that there shall be no play or looseness between the 'detcnator and the charge, without explosion. It is also important to provide th booster-receiving recess with an abutment shoulder accurately positioned to engage the head of the booster or detonator, in

such manner that theinner end of the inserted portion of the latter will abut against the inner end of the recess.

Heretofore, it has been thepractice to form the booster or detonator-recess in the explosive charg by one of several methods. method consists of boring the axial recess by means of a hand drillor a power drill. Another method consists in casting the high explosive around a shaping plug or core. The latter is provided with a cylindrical base the size of the body of the booster or detonator to be used, and an axial proiuberance of the proper ength and diameter to form the fuse-receiving axial recess in the explosive material. Another method is to drive a plug into the open end of the shell by hammer blows, said plug being of approximately V the size of the desired recess. It has also been proposed to fill the shell by pushing the explosive into it by hydraulic pressure and then to form the recess therein. However,- all of these methods are unsatisfactory, the first two for the reason that they are slow, tedious and unsafe, the third because it tends to crack the explosive material, and the last for the reason that the explosive material will contain cracks, holes and coarse crystals, which seriously affect the density and explosive qualities of the shell, and which also leave the shell underweight, and make it subject to premature explosion in the gun.

Furthermore, any method by which a portion of the explosive material is to be removed after the shell has been filled with cast explosive material, involves certain vital requirements. In the first place, great accuracy must be employed, not .only to so position the fuse that the detonator will be in intimate contact with the remaining explosive materiaLthereby to properly detonate the mass, but also to insure that the detonator will not jam when inserted before firing. Secondly, in removing the explosive material occupying the opening in the end of the shell, the material must be cut accurately for the reasons that if too much material is removed the remaining material will not be held in place but will break loose from the walls of the shell, thereby making the detonation ineffective or causing the shell to explode in the gun. This is particularly true with shell in firing. If the materialis only removed to a plane forwardly of the inner end of the fusereceiving opening, the remaining material which extends outwardly to the mouth of the opening is likely to be broken down when the detonator and other parts of the head are placed in position so that the detonator will not go home, thereby causing the explosive to fall into the recess and to jam the detonator. Thirdly, in boring a recess of accurately predetermined depth, it is necessary to determine the depth of therecesses with respect to some accurately machined external part of the stock which bears a known relation to the point or plane to which respect to T. N. T. which tends to slip within the it is desired to bore. In the case of shells of the stant for all shells of a given type and size, and it is therefore essential to determine the depth of bore with relation to the forward edge of the shell. Fourthly, care must be taken to prevent overheating of the explosive material by friction developed during the boring operation, because the material, if heated, will not only "gum up" the cutting tools and thus cut down the speed of production, but will also greatly increase the danger factor. Fifthly, after the fuse bore has been made, .it is necessary as separate operations, to "blow out" the bore with compressed air, or by wiping it to remove all of the dust of the explosive. A sixth and important factor is that the threads of the opening in the shell must be so thoroughly cleaned that no explosive particles will be retained therein, thereby removing possibility of ignition of said particles while the booster or detonator is being inserted into the shell.

One of the objects. of the invention is to provide means for increasing the speed and accuracy 'of the boring operations hereinabove referred to,

and at the same time to materially curtail the danger factor in the production of high explosive projectiles. A further object is to provide a simple and accurate method of boring the explosive materlal to provide the fuse-receiving recess therein. A further object is to provide for effectively and thoroughly cleansing the threaded walls of the fusereceiving opening of the shell as the boring operation progresses, without danger of explosion produced by friction. A further object is to control temperature and prevent overheating of the explosive material during the boring operations.

The invention will be hereinafter fully set forth and particularly pointed out in the claims.

In the accompanying drawings:

Figure 1 is a side elevation, partly in section illustrating an apparatus for practicing the present invention. Figure 2 is a detail sectional view of the air blast control valve. Figure 3 is a side elevation illustrating a slight modification. Figures 4, 5, 6 and 7 are detail views illustratin methods of loading various types 01' projectiles.

Referring to the Figures 1 and 2 of drawings, F designates a supporting frame, which rests upon a base l0, and is provided with an upright body portion ll. Rotatively mounted in bearing I2 is the spindle l3 of a boring machine constructed somewhat similarly to a drill-press, but in this instance, shown in inverted position. Said spindle may be rotated by any desired means. but for purposes of illustration, a driving pulley I4 is shown, the same being driven by a belt l5, actuated from a suitable source of power (not shown). The lower end of the spindle is provided with a reduced portion it, which rests upon the end of a bearing member i7, while the spindle is in its lowermost position.

The spindle l3 may be reciprocated axially in any desired manner, but for purposes of illustration a rock arm RAsuitably pivoted to frame F is shown as connected by means of a link I I with a valve V, which is slidably mounted upon the vertically disposed reduced portion ii. The details and functions of valve V, which is the main fluid-pressure-control, will be later described. The rock arm RA is normally biased to a depressed position by means of a weight W. Said rock arm is connected by a link 20 with an actuating lever 2i, said lever 2| being pivotally mounted ina suitable bracket 23, carried by frame F. An operating handle It depends from sai lever to such a position as to be within easy reach of the operator.

.In Figure 1, for purposes of illustration, a

standard type shell S is shown, the same having a main chamber 8' provided with an internally threaded opening 3 at the nose end, providing an abutment shoulder s. The shell is shown as filled with explosive E.

The boring head or support H for the shell body S comprises a bracket 30 which is detachably secured to the upright portion H of the frame F in suitable manner, as for instance, by means of bolts 3|. Said boring head comprises a receiving-head 32, preferably in the form of a cylindrical chamber, open at both ends, and provided at its lower end with an internally threaded thickened portion 33. Adjustably engaging said last mentioned threaded portion is a collar 34, which is lined with a sleeve 35 of babbitt or other bearing material, the latter being retained in position in any desired manner, set screws 35 being shown for. purposes of illustration. The sleeve 35 is tapered internally to conform to the contour of the nose of the shell, said sleeve 35 and the collar 34 constituting a stop to limit the downward movement of the shell S. The chamber of head 32 is also provided with a second sleeve 35 ofbearing metal to aid in maintaining the shell in vertical alinement with the axis of the spindle l3 During the boring operation to be later described, the shell S is anchored against displacement by means of a clamp ring 40, supported by an arm 4| which is pivotally mounted upon a collar 42, having threaded engagement with a complemental portion 43 of the head 32. Said collar 42 is provided with an annular handle 43 by means of which it may be conveniently'manipulated.

In the form illustrated in Figure 3, the adjusting collar 34 is omitted, and the shell is supported at its lower end by a sleeve 35 having a tapered opening complemental to the end of the shell.

In order to index th proper longitudinal position of the shell S, an indicating device I is employed. For purposes of illustration the indicating device is shown as comprising a bracket a supported by the head 32, and pivotally supporting an arm I). Secured to the outer end of the arm b is a pointer c, which moves over a fixed scale 11, provided with a normal indication e. The other end of arm I) is provided with a finger I positioned to engage the nose of the shell while the latter is supported by the head.

The spindle I3 is provided with an axial bore l5 designed to serve as a conduit for fluid to be supplied under pressure from a suitable source (not shown), through a flexible hose or other suitable conduit 46, delivering through a connecting nipple l1. Said fluid may be delivered at atmospheric temperature or at a reduced temperature, ii. desired. Flow of fluid pressure to the tools, through the bore 45, is controlled by the valve V which is slidably mounted on the reduced portion ii of the spindle l3, and is arranged to abut against shoulder V of said spindle, slidable movement of the valve in one direction along the spindle, being limited by a stop 48 carried by said spindle. Said valve is provided with a chamber 50 connected with the nipple ll. Flow of compressed fluid through the valve V is normally prevented while the spindle is in its lowermost position because the outlet openings SI of chamber 50 are below the plane able magnitude.

of chamber 50, which is formed by a recess in the lower end of the reduced portion 16. While the spindle is at rest, the valve is spaced from shoulder V and flow of air to chamber 50" is prevented. As rock arm RA moves the valve upwardly, the chambers 50 and 50 are brought into register as the top of the valve V engages shoulder V, imparting upward movement to the spindle. The two chambers are so positioned as to continue in register during upward movement of the spindle and thereby maintain a fluid flow through the bore-of the latter. The'nipple 41 engages a fixed slotted guide G, which contains the nipple in proper alinement with the spindle during axial movements'of the latter, and also prevents rotation of the valve V. I

' The boring tool T is also provided with an axial bore 45, which is in register with the bore 45 while the tool is in operation, the head of said tool having radially disposed discharge openings 52 through which the compressed fluid is discharged during the boring operation. In this manner overheating of the explosive is prevented. Said tool is also provided with a counterboring head 53 of the proper diameter to remove explosive from the enlarged opening in the nose of the shell, said head 53 also having radial discharge openings 54 communicating with the axial bore of the tool. Air discharged through the openings 54 also prevents overheating of the explosive dur-' ing the counterboring operation. The periphery of the head 53, at positions between the outer ends of openings 54 is covered with non-sparking material 55, such as fiber, bristles, bronze, or

other suitable brush material which will not produce sparks by reason of its frictional or grinding action contact with metal. Below the head 53 is located a circular centrifugal separating 55.

Supported by a suitable bracket 60 at a position adjacent to but slightly below the head 32, is a separating chamber 6|, open at its top, so that boring particles of explosive material will drop into it during the boring operations. It will be noted that the boring spindle extends upwardly through chamber '6l, the opening through which the spindle extends being suitably packed, as for instance, by means of felt packing 62. The centrifugal separator plate 53 is at all times located within said chamber. During the boringoperations, the heavier particles of explosive will drop on to plate 53, the heavier particles being thrown outwardly therefrom by centrifugal force. and dropping through a conduit 63 into a hopper 63 The fine particles and fumes of explosive which are too light to fall by gravity are poisonous and constitute a serious menace to the health of the operator, and create a danger factor of consider In order to prevent their discharge into theatmosphere, an exhaust conduit 65 leads from the bottom of casing 6|, to a suitable suction device, (not shown) having sufficient power to exert a definite suction influence at the top of the separator casing SI, of sufficient intensity to suck in all of the fumes. fine dust, and light particles in the vicinity of the shell but also to carry off the dust particles developed by the operation of the plate 56. To prevent the discharge of poisonous du t and fumes in the vicinity of the boring tools if the vacuum system should fail or get out of order, the exhaust conduit 65 is provided with a gravity valve 56 which will be held, in open position while under the suction influence of the vacuum system, but will seat itself automatically when such plate influence fails. The valve 56 is connected by a rod 51 with a lever 58, engaging the stem of air valve 69 which is constructed as to be normally unseated by the fluid pressure. The arrangement is such that the seating of valve 66 will also cause rod '61 to simultaneously effect the closing of valve 59. It is to be understood, however, that the ratio of the pressure under which fluid is delivered to the tools, with respect to the suction in conduit 55, must always be in favor of the suction.

In practice, referring more particularly to Figures l and 2, to initially adjust the path of reciprocation of the boring tool T, and to determine the normal position of the pointer 0, either one of the fllowing methds is satisfactory. The first method comprises longitudinally adjusting the only to the plane of the shoulder s Thereafter,

when a new shell is inserted into the head, movement of the pointer to mark e indicates that it is in proper position. The other method comprises adjusting the stop collar 48 to the approximately correct position along the spindle, and then lon-. I

gitudinally adjusting the shell S to the proper position by means of collar 33. After making one or more trial borings to determine the final adjustment, a normal position mark is made at the end of the pointer c, as indicated at e, which thereafter constitutes the normal indicating position.

In operation, the shell S containing it explosive charge E is inserted into the head H, insuch manner as to be supported by the bearing sleeves and 35. If. the pointer c moves to the mark 2, the operator knows that the shell is properly positioned, and will engage the ring 40 with the rear portion of the shell, and adjust it by means of collar 42 until the shell is firmly held in position within the head H. During these operat ons the valve V is-disengaged from shoulder V. The boring operations are carried out by the operator, in the usual drill-press manner by pulling downwardly on the handle 24 and thereby effecting upward feed of the spindle, it being assumed, of course, that the necessary power to rotat the spindle has been turned on. As the valve V is moved upwardly, a corresponding movement i imparted to the spindle by reason of engagement of the valve V with shoulder V. During upward movement of the spindle, the openings in the chambers and 5i] are brought into register, so that cooling fluid may enter the bore of the spindle. Thus, the valve will be caused to travel upwardly with th spindle, and thereby maintain a constant supply of cooling and dust-removing fluid to the tool heads.

As the spindle advances the tool T penetrates the explosive within the opening 3? and passes into the main body of the explosive. As the spindle rises the count rior rg head 53 when is moving upwardly and rotating simultaneously with the tool T, enters said opening s being of such diameter that when the cutter has been advanced to the plane defined by the shoulder s it leaves a very thin ring of explosive material within the opening s This ringiof material is quickly brushed out by the bristles 55, thereby thoroughly cleansing the opening by removing all of the borings from the screw threads, so that usual said removed borings will drop into the separator chamber 5| During the boring operations above described a Suitable cooling fluid is discharged against the explosive, through the hole 52 and 54, respectively, so as to prevent the heating due to friction, thereby permitting a speedy boring operation without scoring the bore and without danger of explosion and/or gumming up of the cutting tools. Th compressed fluid also acts to blow fine particles of explosive out of the bores and the screw threads during the boring operation, thereby greatly assisting in the cleansing operation.

It is to be noted that the counterbore cutter 53 is mounted on the shank of the tool T in such position that when it reaches the plane of the shoulder s (Figure l), the-said tool T will have advanced the proper distance into the explosive body E to conform to the dimensions of the fuse which is to be inserted into the nose of the shell.

Owing to the fact that the shell is supported by means of the tapered bearings complemental to the tapered end thereof, insteadof by means of a ring stop engaging its nose, the space beneath the mouth of the shell is left comparatively open, so that the material cut away by the boring tool can freely fall from the recess and be removed by the suction chamber 6| and suction pipe 65. Thus, the accumulation of explosive material on the usual support disposed beneath the shell is eliminated, thereby avoiding explosions resulting from blows upon this material upon the insertion of new shells into the apparatus. Moreover, no -mounds can accumulate upon the shell support, to give the shell a false height relative to the travel of the boring tool. This is a desirable arrangement, although not essential. In other words, the invention is not limited to this specific way of supporting the shell, as will later appear.

The invention as thus far described has been directed to operations in connection with a particular type of shell which has a threaded opening in the nose thereof toreceive the fuse or detonator, said opening being provided with a shoulder s acting as an abutment for the head of said fuse or detonator. This example was selected for illustrativepurposes only, and it is to be understood that the invention is equally applicable to work upon shells of the base fuse type irrespective of whether the abutment shoulder is present or not. For purposes of illustration, the apparatus and method herein described have been discussed with relation to the manufacture of high explosive shells, but they are not to be considered as limited in this respect, because they are equally applicable to the loading of bombsgfboosters and other explosive projectiles, or parts thereof which carry explosive material.

In Figure 4 is illustrated a modification in which a shell S of the nose detonator type is supported in horizontal position during the boring operations incident to the formation of the detonator receiving recess within the explosive material. The shell S is of the same general type as the shell S illustrated in Figure 1, except that the abutment shoulder s is omitted. The operation of Figure 3 differs from that of Figure 1 only to the extent that they are carried on while the shell is in horizontal position instead of vertical position. Referring more particularly to said Figure 3, the shell holder H is provided with bearings h in which the shell is nested in a horizontal position, and is held against axial movement by means of the cap 71. held in engagement with the butt end of the shell by means of the locking device h. The boring head 53 and the counterboring head 54 are the same as in Figure 1, and the mechanism for operating said boring heads will preferably be the same as already described in connection with Figure 1. It will be also observed that-the nose end of the shell projects into a suction chamber 6|- which is provided with a suction conduit and is disposed over a hopper 63 so as to provide for the effective removal of the dust and fumes as well as the broken particles which are dislodged from the explosive material E during the boring operation.

In Figure 5 is illustrated a method which may be employed in the loading of bombs. Referring to said figure, B designates a bomb of the aerial type provided with a detonator receiving opening 10 in the butt end thereof. The boring heads 53 and 54 may be the same as heretofore described and the spindle rotated by suitable means diagrammatically illustrated at O and operating in substantially the same-manner as the apparatus disclosed in Figures 1 and 4. The suction chamber 6| and the exhaust conduit 65 may be the same as heretofore described. It is to be understood that the bomb is to be suitably supported during the boring operations, and such a support is indicated at 11*.

In Figure 6 is illustrated another method of loading a shell, in this instance the shell S being of the base detonator type. That is, it is provided with a detonator receiving opening H in the base, the shell being preferably held in vertical position by means of a head H resting upon a bracket 12 and clamped in place by an anchoring member 13. The vacuum chamber 6! with the vacuum conduit 65 and the gravity conduit 83 are preferably also used. The boring heads 53 and 54 are the same as in the views previously described and the same is true of the operating mechanism indicated at O.

In Figure 7 the method is shown as applied to the boring of a detonator cavity within a booster or detonator of the type used in the contact explosion of shells. Referring to said figure, which is more or less diagrammatic in character, the booster S is partially filled with explosive E and is to be provided with an axial recess I3 to receive a detonating element not shown. The booster is supported by a suitable holder H carried by a bracket 14, the booster being anchored by means of an adjustable block I5. The boring I heads 54 and 55,, the suction chamber 6|, with the suction conduit 65 and gravity conduit 63, together with the operating mechanism 0', are as already described in connection with the other figures.

It will be readily understood from the foregoing that the present method and apparatus, as herein described, are not limited to any particular type of projectile, and therefore, wherever the terms "shell or "shell body are used in the specification and claims, said terms are intended not only to include the specific type of projectiles usually identified as shells, but any other equivalent or explosive device in which it is necessary to provide a cavity within the explosive material for the reception of a detonating device.

It is also to be understood that while it is preferred to use compressed air as the cooling fluid to be sprayed upon the explosive surfaces during the boring thereof, the invention is not limited in this respect because any other gas or liquid which is chemically inert with respect to the explosive material may also be used. If desired,

the compressed fluid system hereinabove described may be used to spray a protective coating, such as shellac, over the bored surfaces.

Having thus explained the nature of the invention and described an operative manner of constructing and using the same, although without I attempting to set forth all of the forms in which it may be made, or all of the forms of its use, what is claimed is:

l. A. device for forming a detonator-receiving cavity in high explosive material while contained within a shell, comprising means for supporting the shell, an axially-movable boring spindle, a hollow cutting tool removably connected with said spindle, said tool having radial discharge openings communicating with said hollow tool, means for operating said spindle, means associated with said spindle for supplying a cooling fluid under pressure to said tool and in such manner as to be discharged from said openings against the adjacent explosive material, and brush means carried by said cutting tool.

2. A device for forming a detonator-receiving cavity in high explosive material while contained within a shell, comprising means for supporting the shell, an axially movable boring sp ndle, a hollow tool having a boring cutter and a counterboring cutter, said tool having eating with said conduit, each cutter having discharge openings communicating with said and so disposed as to project outgoing cooling fluid against adjacent surfaces of the explosive material during the boring operation, non-spark brush means carried by the periphery of the counterbore cutter, and means for supplying said 3. .A device for forming a detonator-receiving cavity in high explosive material while contained within a shell, comprising means for supporting the shell, an axially movable boring spindle, having a longitudinal conduit extending therethrough, means for supplying a cooling fluid to a bore communi bore ing a longitudinal conduit extending therethrough,.means for supplying a cooling fluid to said conduit, a normally unseated valve controlling flow of fluid to said conduit, a hollow cutting tool communicating with said conduit and provided with discharge openings, a separating chamber so arranged as to receive the borings as they are discharged during the boring operation, a suction conduit connnected with said chamber, a check valve in said suction conduit so arranged as to be unseated by the suction influence, and means operable by the seating of said check valve for automatically seating said fluid control valve.

6. A device for forming a detonator-cavity in a shell, said shell including a casing having a threaded opening in one end, and filled with a solid explosive material, said device including means for supporting the shell, a tool having a boring cutter and counterboring cutter, means for moving the tool into and out of the opening in the shell for forming the detonator-cavity in the explosive material, the counterboring cutter being of approximately the same diameter as the diameter of the opening in the shell but of a size to clear the wall of said opening during the cutting operations, a brush carried by the periphery of the counterboring cutter and positioned to engage the threads of the opening in said shell, so as to remove explosive material adhering thereto after the detonator cavity has been produced, and means for conducting away the explosive material removed by said brush.

'7. A device for forming a detonator-receiving cavity in high explosive material while contained said conduit, a hollow cutting tool communicat- 0 ing with said conduit and provided with discharge openings, 2. separating chamber so arranged as to receive the borings as they are discharged during theboring operation, a suction conduit connected with said chamber, a check valve in said suction conduit so arranged as to be unseated by the suction influence, and means operable by the seating of said valve for cutting off flow of fluid to said spindle.

4. A device for forming a detonator-receiving cavity in high explosive material while contained within a shell, comprising means for supporting the shell, an axially movable boring spindle, having a longitudinal conduit extending therethrough, means for supplying a cooling fluid to said conduit, a valve operated by the axial movement of the spindle for controlling the flow of said cooling fluid through the spindle, a hollow cutting toolrcommunicating with said conduit and provided with discharge openings, 9. separating chamber so arranged as to receive the borings as they are discharged during the boring operation, a suction conduit connected with said chamber, a check valve in said suction conduit so arranged as to be unseated by the suction influence, and means operable by the seating of said valve for cutting 01! flow of fluid to the first mentioned control valve.

5. A device for forming a detonator-receiving cavity in high explosive material while contained within a shell, comprising means for supporting the shell, an axially movable boring spindle, havsive material during Within a shell, comprising means for supporting the shell, an axially movable boring spindle having a longitudinal conduit extending therethrough, means for supplying a cooling fluid to said conduit, a hollow cutting tool communicating with said conduit, said tool having discharge openings so disposed as to project outgoing coo-ling fluid against adjacent surfaces of the explothe boring operation, a valve for controlling the supply of said fluid, said valve including a control member slidingly movable on said spindle, means for normally maintaining said valve control member in valve-closed position, and means for moving said control member along the spindle toward the Work to open the valve, said spindle and said valve control member having complemental means for imparting axial movement to the spindle as the control member is further moved in the direction of the work, following opening of the valve.

8. A device for forming a detonator-receiving' cavity in high explosive material while contained within a shell, having in combination means for supporting the shell, an axially movable borin spindle, a separating chamber having an open top portion adjacent to the shell supporting means, a boring tool locateed within said separating chamber, a suction pipe leading from said separating chamber to suck lighter particles and fumes of explosive into said chamber from the vicinity of the shell, means located in the separating chamber for separating the lighter constituents of the borings from the heavier constituents thereof, so that said lighter constituents may be withdrawn through said suction pipe, and a. conduit communicating with the separating chamber I ULDRIC THOMPSON, JR. 

